Tension device.



J. V. ALLEN.

TENSION DEVICE.

APPLICATION FILED APR. 7, 1909.

1,149,244. Patented Aug. 10, 1915.

yMziL/fiam m imw COLUMBIA PLANOGRAPH c0-,WA5H|NOT UMTEDSTATES JOHNV. ALLEN, E SOUTH WEYMOUTH, MASSACHUSETTS, ASsIGNoE roaulvnrEn srroEv- MACHINERY COMPANY, or PATERSON, NEW JERSEY, a conroEA'rIon oEivEw' JERSEY;

To all whom-it mayconoern Beit known that I, JoI-IN V. ALLEN, a citizen of the United States, residing at South WVeymouth, the county of Norfolk and State of Massachusetts, have invented certain new and useiul Improvements in Tension Devices; and I doihereby declare.

the following to be a-full, clear, and exact description of the invention, such as will enable others skilled in the art to which it-appertains to make and use the same.

The present invention relates to tension devices for impartinga yielding resistance to the thread of sewing machines and other machines employing a thread or cord; Here'- toi'ore devices for accomplishing this result have comprised as a general rulea rotatable member with which the thread was held in frictional engagement, and some suitable friction device for retarding the rotation of such member. Such constructions, however, have beenfound defective in operation in that thethread being held simply in rfrictional engagement with the rotatable mem ber tended to slip thereon, even when the thread was passed" completely around the ro' tating mem er one or more times or the tlirea d receiving groove in said member was so shapedthat the thread had a wedging or gripping action therein;

One of the objects of the present inventionis to provide a tension device which will impart a uniforniand unvary'ing resistance or tension to the thread oi the desired and predetermined amount, and this result is accomplished; broadly speaking, by means of a rotatable'thread member, the rotation of which is restrained or retarded by some suitable friction device, mechanism being provided for clamping, the thread to such member, so that all slipping of the threadon the member is absolutely prevented and the desired amount of resistance or tension is invariably obtained.

Another defectpresent in the prior devices where the thread-receiving groove of the rotatable member wasfna rrow or V- shaped, so that the thread would have a wedging. or gripping action, andthe thread made one or" more complete turns around such member, was that a chafingor abrading action of the thread up'on itself" ,wou-ldYbe produced at the point where the-threadwa s delivered fi'onithe"bottbm'ofthe groo'veand TENSION n vIoE.

from beneath overlying turns to the sewing machine proper. Where wax orot-her ma;

terial' was applied to the thread before it" reached the tension device, not only the wedging action of" the thread in the groove but'the chafing of the thread'upon-itseli tended to remove or strip the wax from the;

to provide a tension device which cannot chafe or abrade the thread,-which shall have a minimum stripping action upon the waxon the thread, and which shall have little tendency to clog or gum up with wax. These objects are accomplished by so constructing the tension device that the thread is gripped or clamped to the rotatable member, thus avoiding the necessity of a narrow or V- shaped thread-receiving groove, orof lead- Spflcifiation of Letters Int I Patented, Augio, 1915 V j Application filed April 7,1909; seri n a g I ing the thread out from beneath one or more superimposed turns'or layers thereof,'-andby so constructing the gripping or clamping means that only a very small portion ofthe threadis held under pressure. Still another defect inherent in the devices of the prior art, and particularlyobjectionable in these devices when used upon high speed sewing machines where the thread is intermittently drawn through the tension device at exceedingly shortmtervalsoftime,

is the necessity of starting the rotatable member from a position of rest, causingit to attain a high angular velocity, and then bringing it to a full stop, all in an exceed inglyshort space of time.

The present invention seeks to avoid the very objectionable inertia eflects due to such a manner of operation by so constructing the tension device that the peripheral speed or angular velocity of the rotatable member shall be less than the linear speed'of the:

thread delivered up by it. Briefly, this is accomplished by providing the rotatable member with a plurality of alternating projections and recesses over and into which the thread is foldedon crimped by suitabledevices, thus enablingthe tension device to give up its thread from such loops or folds,

at a higher linear ratezthanwhereth j;thr isheld by the rotatable member. i Craig na'rymanner.

the" accompanying. drawings. which; i

illustratethepreferred embodiment of the present invention devised for use in connection with a chain-stitch, wax-thread," shoe-sew ng-;mach1ne ofathe Goodyear type, Figurel shows 1n side elevation a por-.

tion of the head and column of such a sewing machine and the tensiondevice attached thereto; Fig. 2 shows in top plan the de-' i vice'as attached; and Fig. 3 shows the ten secured to the rear portion ofthe head by jsion device detached in side-elevation and looking in the opposite directlon from ;l f -.l'-

As shown in drawings, lrepresents the head of the sewing machine and 2 the column or support for the same Rigldly 7 thebolts 3 is the tension device which com prises, briefiy, Y Y member mounted thereon, a friction device forreta-rding the rotatlon of said member,

guiding means for guiding the thread to the:

rotatable member, and clampingmeans for f clamping the thread to said member.

line, the points or crownsof the teeth being r somewhatj rounded, and the recesses or. 7 intervals 10 between the teeth being some- The frame is indicated by the reference charactera and is provided at its rear end with the. open slot or recess 5 and the vertical and the downwardly extending arms 6 y and 7, respectively. The rotatable thread member is shown at 8 and is provided on ts periphery with a plurality of projections 9 which resemble gear teeth in shape or outwhat wider, than with ordinary gearing, for purposes hereinafter to be stated. The thread member 8 is rotatably mounted upon the shaft or stud 11 located inthe slot 5 of the frame and securelyclamped to the frame by means of the washer and nut 12 and l3, respectively.

The friction device for retarding the rotation of the, thread member 8 comprises two 7 tially Chapelle .No. 488,505, dated December 20th, I

felt washers 14, one on each side ofthe member and held in engagement therewith on one side by the washer 15 (see Fig. 3) 1 and "on the other by the spring pressed washer or block 16. The washer-l5 is held from rotation by being clamped between the frame and the shoulder on the shaft, while 7 the block or washer 16,. although free to move along the shaft 11,.is prevented from turning with the thread member by means of the rounded eXtremities 17 of the forked end of the. tension release lever 18, these ends engaging correspondingly shaped recesses 19 formed in the spring block 16. The tension release mechanism is substanlike. that shown in the patent to La 1892, and therefore need not be described .in detail. Surrounding the shaft 11 is the openxspring 20, one end of which engages the? block 161 while the other end bearsagainst the adjusting wheeler nut 21 on the a frame, a rotatable thread.

threaded end of the shaft, a lock 22 being provided for locking the adjusting "nutin the desired position;

As'shown in Fig. 2, the projections, or.

teeth .of the thread member are formed parallel with the axis of rotation and without any groove or slot therein, and in order to guide the thread properly on to these peripheral projections or teeth, a grooved thread truck 23 is pivotally mounted upon the downwardly "projecting arm 7 around which truck the thread 24 passes.

The clamping device for. gripping or' clamping the thread tothe thread member is shown inthe drawings as a freely rotatable wheel 25, also provided on. its periphery with projections orteeth 26 corresponding in outline to the projections 9 on 1 the thread member 8, the recesses 27 between the teeth26 being formed like the recesses 10 on the thread member 8' of greater width than the teeth.

The wheel 25 isrotatably mounted upon the stud 28 secured in the swinging arm 29.

which in turn is pivoted on the stud 30 in the frame at of the tension device. The lever 29 is held fromtinovementby means of a latch 31 pivoted on the stud 32 passing through the slot 83 in the arm 6 of the i frame, the "front end of the latch being provided with a notch or recess 34 to engage the projecting end of thestud 28 upon which the wheel 25 rotates. By means of the slot 7 33 the pivotof the latch 31 may be moved toward or from the head of the sewing pot or directly from some suitable source of supply, over the guide truck 23, thence around the front of the thread member'S,

I between that member and the wheel 25, then partially around the wheel, from fwhichit passes to the head of the sewing machine.

The object of making the recesses 10 and 27 of greater width than the projections or teeth 26 and 9 which enter them, is so that the thread may be easily crimped or folded over the projectionsand down intov the recesses, these latter being sufliciently wide to permit this to be done Without bringing any considerable pressure .upon that portion of the thread between the sides of, adjacent projections or. teeth and between the tops'of the teeth and bottoms of the recesses on themember 8 and wheel 25. The rounding of the teeth isto avoid all possibility of cutting ofthe thread in the clamping operation. c I j The mode of operation of this tension de tion, the pivot for the latch will be adjusted to give the requisite depth of intermesh and the nut 21 will be turned to apply the de sired amount of tension. If the sewing machine be now set in operation and the thread be. drawn upon by the thread handling instrumentalities, the very first movement of the thread will cause the freely rotatable wheel 25 to turn slightly, causing the advancing faces of its projections or teeth to securely grip or clamp the thread against the following faces of the thread member 8, thus preventing all further movement of the thread except when accompanied by a movement of the thread member 8. The greater the strain exerted upon the thread, the more securely will it be 'gripped or locked be tween the projections or teeth on the wheel 25 and those on the thread member 8, so that all slipping of the thread and any variation from the desired and predetermined amount of tension are rendered impossible. Since only a very small portion of the thread is actually subjected to this clamping or gripping action, very little of the wax applied to the thread is squeezed out of or stripped from the same, which results not only in the thread being delivered with a greater quantity of wax, but also greatly reducing the amount left upon the tension device. Furthermore, by reason of the construction of the parts, there is little, if any, liability of the device to gum or clog up with wax or in any other way to have its operation in-. terfered with. It is obvious that as the thread member rotates and delivers up thread, a very considerably greater length of thread will be freed, say by a rotation equivalent to the peripheral distance between two adjacent projections or teeth, than if the thread was held in a circular groove in the ordinary and usual manner.

The greater the depth of intermesh and the,

larger the number of projections or teeth, the greater will this thread excess become and the slower will be the rate of rotation of the thread member relatively to the rate of delivery of the thread, or, to put it in another way, the higher will be the rate of delivery of the thread for a given rate of rotation of the thread member, thus adapting the device particularly to high speed machines, as already pointed out.

Having thus described the construction form of the present invention as applied to a particular type of machine, what is claimed is:

1. A tension device, having, in combination, a pair of intermeshing spur gear wheels between which the thread is laid, adjusting devices for positively limiting the depth of intermesh, and a friction device for retarding the rotation of one of said wheels, substantially as described.

2. A thread delivery controlling device, having, in combination, a pair of intermeshing spur gears between which the thread is laid, means for positively limiting the depth of intermesh, and means for controlling the rotation of one of said gears, substantially as described.

3. A thread delivery controlling device, having, in combination, a pair of intermeshing spur gears having relatively narrow teeth and wide spaces between the teeth to permit the gear teeth to grip the thread at separated points along the thread between the following face of the tooth of one gear, and the advancing face of the tooth of the other gear, means for controlling the rotation of said first mentioned gear, and means for positively limiting the depth of intermesh substantially as described.

4. A tension device, having, in combination, a rotatable thread member provided with a plurality of projections and recesses, a friction device for retarding the rotation of said member, a second rotatable member having projections and recesses arranged to intermesh with the recesses and projections on the thread member, to carry the thread over the projections and into the recesses on said members, a pivoted lever supporting the second member, and mechanism for ad justing the lever about its pivot to vary the depth of intermesh of the projections and recesses, to alter the linear speed of the thread relative to the peripheral speed of said members, substantially as described.

5. A thread delivery controlling device, having in combination, intermeshing gears between which the thread is laid, means for controlling the rotation of one of said gears, and means for supporting the gears to allow a rotary movement of one gear with relation to the other under a strain on the thread to clamp the thread, substantially as described.

In testimony whereof, I afiix my signa ture, in presence of two witnesses.

JOHN V. ALLEN.

Witnesses: ALFRED H. HILDRETH, ANNIE C. RICHARDSON.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G. 

